busybox/loginutils/chpasswd.c
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   1/* vi: set sw=4 ts=4: */
   2/*
   3 * chpasswd.c
   4 *
   5 * Written for SLIND (from passwd.c) by Alexander Shishkin <virtuoso@slind.org>
   6 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   7 */
   8//config:config CHPASSWD
   9//config:       bool "chpasswd (18 kb)"
  10//config:       default y
  11//config:       help
  12//config:       Reads a file of user name and password pairs from standard input
  13//config:       and uses this information to update a group of existing users.
  14//config:
  15//config:config FEATURE_DEFAULT_PASSWD_ALGO
  16//config:       string "Default encryption method (passwd -a, cryptpw -m, chpasswd -c ALG)"
  17//config:       default "des"
  18//config:       depends on PASSWD || CRYPTPW || CHPASSWD
  19//config:       help
  20//config:       Possible choices are "d[es]", "m[d5]", "s[ha256]" or "sha512".
  21
  22//applet:IF_CHPASSWD(APPLET(chpasswd, BB_DIR_USR_SBIN, BB_SUID_DROP))
  23
  24//kbuild:lib-$(CONFIG_CHPASSWD) += chpasswd.o
  25
  26//usage:#define chpasswd_trivial_usage
  27//usage:        IF_LONG_OPTS("[--md5|--encrypted|--crypt-method|--root]") IF_NOT_LONG_OPTS("[-m|-e|-c|-R]")
  28//usage:#define chpasswd_full_usage "\n\n"
  29//usage:       "Read user:password from stdin and update /etc/passwd\n"
  30//usage:        IF_LONG_OPTS(
  31//usage:     "\n        -e,--encrypted          Supplied passwords are in encrypted form"
  32//usage:     "\n        -m,--md5                Encrypt using md5, not des"
  33//usage:     "\n        -c,--crypt-method ALG   "CRYPT_METHODS_HELP_STR
  34//usage:     "\n        -R,--root DIR           Directory to chroot into"
  35//usage:        )
  36//usage:        IF_NOT_LONG_OPTS(
  37//usage:     "\n        -e      Supplied passwords are in encrypted form"
  38//usage:     "\n        -m      Encrypt using md5, not des"
  39//usage:     "\n        -c ALG  "CRYPT_METHODS_HELP_STR
  40//usage:     "\n        -R DIR  Directory to chroot into"
  41//usage:        )
  42
  43#include "libbb.h"
  44
  45#if ENABLE_LONG_OPTS
  46static const char chpasswd_longopts[] ALIGN1 =
  47        "encrypted\0"    No_argument       "e"
  48        "md5\0"          No_argument       "m"
  49        "crypt-method\0" Required_argument "c"
  50        "root\0"         Required_argument "R"
  51        ;
  52#endif
  53
  54#define OPT_ENC  1
  55#define OPT_MD5  2
  56
  57int chpasswd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  58int chpasswd_main(int argc UNUSED_PARAM, char **argv)
  59{
  60        char *name;
  61        const char *algo = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
  62        const char *root = NULL;
  63        int opt;
  64
  65        if (getuid() != 0)
  66                bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
  67
  68        opt = getopt32long(argv, "^" "emc:R:" "\0" "m--ec:e--mc:c--em",
  69                        chpasswd_longopts,
  70                        &algo, &root
  71        );
  72
  73        if (root) {
  74                xchroot(root);
  75        }
  76
  77        while ((name = xmalloc_fgetline(stdin)) != NULL) {
  78                char *free_me;
  79                char *pass;
  80                int rc;
  81
  82                pass = strchr(name, ':');
  83                if (!pass)
  84                        bb_error_msg_and_die("missing new password");
  85                *pass++ = '\0';
  86
  87                xuname2uid(name); /* dies if there is no such user */
  88
  89                free_me = NULL;
  90                if (!(opt & OPT_ENC)) {
  91                        char salt[MAX_PW_SALT_LEN];
  92
  93                        if (opt & OPT_MD5) {
  94                                /* Force MD5 if the -m flag is set */
  95                                algo = "md5";
  96                        }
  97
  98                        crypt_make_pw_salt(salt, algo);
  99                        free_me = pass = pw_encrypt(pass, salt, 0);
 100                }
 101
 102                /* This is rather complex: if user is not found in /etc/shadow,
 103                 * we try to find & change his passwd in /etc/passwd */
 104#if ENABLE_FEATURE_SHADOWPASSWDS
 105                rc = update_passwd(bb_path_shadow_file, name, pass, NULL);
 106                if (rc > 0) /* password in /etc/shadow was updated */
 107                        pass = (char*)"x";
 108                if (rc >= 0)
 109                        /* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
 110#endif
 111                        rc = update_passwd(bb_path_passwd_file, name, pass, NULL);
 112                /* LOGMODE_BOTH logs to syslog also */
 113                logmode = LOGMODE_BOTH;
 114                if (rc < 0)
 115                        bb_error_msg_and_die("an error occurred updating password for %s", name);
 116                if (rc)
 117                        bb_error_msg("password for '%s' changed", name);
 118                logmode = LOGMODE_STDIO;
 119                free(name);
 120                free(free_me);
 121        }
 122        return EXIT_SUCCESS;
 123}
 124